1. Field of the Invention
The present invention relates to a camera array (as known as camera array system, multiple lens camera, and the like) that performs photographing with a plurality of cameras arranged.
2. Description of the Related Art
In recent years, a technology has been developed that uses the so-called camera array where a plurality of imaging devices such as digital cameras is arranged. By performing photographing with a camera array to acquire three-dimensional information on a subject, it is possible to generate image data indicating an image of an arbitrary viewpoint or a line-of-sight direction and to generate image data indicating a parallax image for the display of a three-dimensional image. It is also possible to generate image data indicating an image in which, after photographing, a focus position and a depth of field have been changed.
There is a technology for acquiring more pieces of subject information by performing photographing with the camera array described above while changing not only the position of each camera and the direction of an optical axis but also photographing conditions.
For example, Japanese Patent Laid-Open No. 2005-51318 discloses a method of performing photographing while changing the focus position and the exposure of each camera.
Japanese Patent Laid-Open No. 2008-128771 discloses a method of performing photographing with an optical filter having a different spectral transmission characteristic attached to each camera and thereby acquiring spectral information on a subject.
However, in the technology disclosed in Japanese Patent Laid-Open No. 2005-51318, the acquired color information is the same in all cameras (for example, RGB values). Hence, when a plurality of sheets of images is combined, many pieces of redundant data are wastefully and disadvantageously contained.
In the technology disclosed in Japanese Patent Laid-Open No. 2008-128771, the color information on the image photographed by each camera is acquired through the color filter having a different characteristic. Hence, even when the same subject is photographed, the pixel value of the image data differs from camera to camera, and thus the accuracy of the calculation of a corresponding point between the cameras is disadvantageously reduced.